CEMENT

This study investigated the effect of partially replacing Ordinary Portland Cement (OPC) with eggshell powder (ESP) in concrete production as a sustainable approach to reduce cement consumption and utilize agricultural waste. The aim of the study was to evaluate the performance of concrete containing eggshell powder as a partial replacement for cement. The specific objectives were to determine the workability of concrete containing varying proportions of ESP, evaluate its compressive strength, assess its water absorption capacity as an indicator of durability, and identify the optimal ESP replacement level that yields the best concrete performance. The experimental study was conducted by preparing concrete mixes with 0%, 5%, 10%, 15%, and 20% replacement of cement with eggshell powder. Waste eggshells were collected, cleaned, dried, ground into fine powder, and sieved before use. Concrete cubes were cast and cured in water, after which several laboratory tests were performed. Workability of the fresh concrete was determined using the slump test, compressive strength was measured at 7, 14, and 28 days using a compression testing machine, and water absorption tests were carried out at 28 days to evaluate the durability-related properties of the hardened concrete.The results showed that workability slightly increased at 5% ESP replacement, indicating improved particle packing within the mix, but gradually decreased at higher replacement levels due to increased water demand of the fine ESP particles. The compressive strength of the concrete improved at moderate replacement levels, with the optimum strength obtained at 15% ESP replacement after 28 days of curing, while further increase in ESP content led to a reduction in strength. The water absorption values for all concrete mixes were below 10%, indicating that the inclusion of ESP did not adversely affect the durability of the concrete. Based on the findings, the study concluded that eggshell powder can effectively replace cement up to 15% without significantly compromising the essential properties of concrete. It is therefore recommended that ESP be considered as a sustainable partial cement replacement material in concrete production, particularly for applications such as pavements, floor screeds, and foundations, where environmentally friendly and cost-effective construction materials are desirable

All over Nigeria as well as to the overseas the fuel oils as well as crude oils are transported through distribution pipes, tankers cargo ships. Although the processes are well laid out to avoid leakages of pipes, accidents of service tankers these events still happens on a regular bases especially in the niger delta region of the country where pipe vandalism due to oil bunkery is on the rise. All these processes leads to the leakages of fuel oils e.g kerosene which eventually settles on coastal waters. The leaked oil products would result in contaminating the water which are used in the concrete mortar and the sandcrete industry which are the cement dependent industry. In this study, the effect of water contaminated with kerosene on the compressive strength of conventional normal ordinary Portland cement has been evaluated in various exposure conditions. Kerosene (0, 2, 4 and 6%) by weight of water) was used to contaminate water to prepare cement mortar cubes specimens. A number of nine uncontaminated samples were prepared with fresh water. A number of nine samples each were prepared with contaminated water at 2%, 4%, 6% Kerosene replacement. Three samples each of percentage replacement and three uncontaminated samples were crushed at the age of three days, seven days and 28 days of curing. From the results gotten the maximum reduction in the compressive strength of 9.21% occurred at the six percentage contamination at the age of seven days. From results obtained it was seen that as the percentage of contamination increase the compressive strength decreased.